III! 1 t "\ LIBRARY Connecticut Agricultural College vol. II $ 04 CLASS NO. h3t>.-l C74 Please wdle *Ws volume ban vacate. 0-74 I 9 F04- \ ill S3 01 c lt.74Q This book may be kept out TWO WEEKS )nly and is subject to a fine of TWO SNTS a day thereafter. It will be 1 on the day indicated below. 1 6 my J9?7 ; 193t ^38 MANUAL OF DAIRY CATTLE BREEDING Digitized by the Internet Archive in 2013 http://archive.org/details/manualofdairycatOOgowe MANUAL OF DAIRY CATTLE BREEDING JOHN W. COWEN, Ph.D. Maine Agricultural Experiment Station BALTIMORE THE WILLIAMS & WILKINS COMPANY 1925 Copyright 1925 THE WILLIAMS & WILKINS COMPANY / 1 S 01 Made in United States of America PUBLISHED SEPTEMBER, 1925 COMPOSED AND PRINTED AT THE WAVERLY PRESS FOR The Williams & Wilkins Company Baltimore, Md., U. S. A. CONTENTS Preface 7 Chapter I Origin and Early History of Breeds of Dairy Cattle 9 Chapter II Development of Registration as a Means of Isolating and Per- petuating Breeds 11 Chapter III Breeds of Dairy Cattle and Mode of Recording in Each Breed 12 Chapter IV Development of Productivity Registers 30 Chapter V Tracing a Pedigree 32 Chapter VI Organizing a Good Sales Pedigree 41 Chapter VII Characteristics of Pedigrees in the Different Breeds, Inbreeding. 43 Chapter VIII Characteristics of Pedigrees for the Different Breeds, Kinship.. 50 Chapter IX Characteristics of Pedigrees for the Different Breeds. Homozy- gosis Resulting from Different Types of Matings 55 Chapter X Characteristics of Pedigrees, Famous Ancestors 66 Chapter XI Conformation in Relation to Milk Yield 73 Chapter XII Age of the Cow in Relation to Milk Yield 77 5 6 CONTENTS Chapter XIII Age of the Cow in Relation to the Butter-fat Percentage 88 Chapter XIV Mode of Secretion of Milk in the Udder 92 Chapter XV Permanence of Milk Yield and Butter-fat Percentage 93 Chapter XVI Inheritance of Milk Yield from Dam to Daughter 99 Chapter XVII Influence of the Grandparents on the Granddaughters' Milk Yield 101 Chapter XVIII The Inheritance of Milk Yield and Butter-fat Percentage in Crosses of Animals Differing Widely in the Amounts of These Variables „ 103 Chapter XIX The Chromosome Mechanism of Heredity in Relation to Dairy Cattle Inheritance 105 Bibliography of Cattle Inheritance 107 PREFACE This manual is prepared as a laboratory text for students pri- marily interested in dairy cattle breeding. A good training is desirable in the elements of biology including courses in pure gen- etics, cytology, and the mathematics of statistics before commencing this work in the agricultural college. Desirable students need not be excluded from the course, however, if they lack courses in these subjects. It will simply mean that such students will have to do outside reading in such texts as T. H. Morgan, 1919, Physical Basis of Heredity, Lippincott Company, Philadelphia; T. H. Morgan, A. H. Sturtevant, H. J. Muller, and C. A. Bridges, 1915, The Mechanism of Mendelian Heredity, Henry Holt and Company, New York; Babcock and Clauson, 1918, Genetics in Relation to Agriculture, McGraw-Hill Book Company, New York; G. Udny Yule, 1919, fifth edition, An Introduction to the Theory of Statistics, Lippincott Company, Philadelphia. The basis for the lecture course to accompany the laboratory course is found in the text, Milk Secretion, 1924 (Williams and Wil- kins Company, Baltimore). The citations to reading in this text are indicated by the abbreviations M . S. The citations to other sources are indicated by rather complete references. No effort is made to give references to general genetic or physiological literature as it is believed that these courses are better given in the pure science sec- tions of the University than in the Agricultural College proper. It is fairly obvious in a course of this kind, necessarily limited for time, that the work had better be confined in general to one breed of dairy cattle. This breed may be changed from year to year indicating to the student that the results for, the different breeds correspond quite closely in the principles involved. By following through this outline with dairy cattle the student will obtain an excellent foundation on which to study similar problems in other types of livestock, horses, sheep, swine, etc. A rather complete list of papers relating to cattle breeding is found in the bibliography. CHAPTER I Origin and Early History of Breeds of Dairy Cattle It is important in any consideration of a breeding problem to have a firm grounding in the mode by which the breed originated. A review of the early history of the dairy breeds will reveal : 1. Origin of the parental stock. 2. Probable inbreeding which took place. 3. Chances for homozygous and heterozygous stock. 4. Breeding measures adopted which would be likely to influence color, type, milk yield, and butter-fat percentage. 5. Other points of importance to breeding problem. Review history of formative period of the different breeds from this point of view. The opportunity is a good one for bringing out the judgment of the student in making a critical unbiassed review. REFERENCES Numerous sources of information will suggest themselves to the instructor. Cole, L. J., and Jones, L. V. H. 1920. The Occurrence of Red Calves in Black Breeds of Cattle, Wisconsin Bulletin 313, for critical review of the Hol- stein-Friesian breed's origin. A review of this is given in Chapter I of M. S. Youatt, William. Stock Raising Manual, brings out important points concerning the early breeder's ideals. Wallace, Robeet. 1907. Farm Live Stock of Great Britain, Edinburgh, gives a brief review of all the breed histories in so far as the British Isles influenced them. Wilson, James. The Evolution of British Cattle and the Fashioning of the Breeds. Sanders, J. 1887. Breeds of Live Stock and the Principles of Heredity, Chicago. The early herd books of the breed associations and the informa- tion which may be obtained from these associations furnish other sources of data for the study of breed origin. Credit is to be given for all other sources of information which you are able to find. Write a 500-word paper on this subject for the breed chosen using as your guide the five points indicated above. Have the reference 9 10 MANUAL OF DAIRY CATTLE BREEDING to the original literature in clear standard form, name of author, date of publication, the title of article or book, place of publication, volume number, and pages. It might be advisable to have different students take different breeds. The reading and discussion of the best papers furnishes an excellent means of fixing this information. CHAPTER II Development of Registration as a Means of Isolating and Perpetuating Breeds A large proportion of the data collected for Chapter I can also be used for this chapter. The problem should be considered from the viewpoint of how registration has influenced the breeding problems of dairy cattle. Data should be included to show when the breed organization took place; what breeds, if any, were used to form the modern breed; under what conditions cattle were ad- mitted to registry; etc. Define the difference between registered, purebred, grade, and scrub members of the breed. Write a 500- word paper on one of the dairy breeds. The best papers may be read before the class and discussed in the laboratory period. REFERENCES Besides those indicated in chapter (I) we might add Col. Le Oonteur, Col. O. P. Cornu, and Thornton, 1845, 1851, 1855, 1859, some references in Journal Royal Agricultural Society of England, volumes V, XII, XVII, XX. Hottsman, W. Cattle Breeds and Management, Vinton & Co., London. The early breed histories as contained in the herd books and such modern standard tests as: Eckles, C. H., and Wakren, G. F. 1916. Dairy Farming, Macmillan & Co. Plumb, Charles Sumner. Rev. ed., 1920. Types and Breeds of Farm Ani- mals, Ginn & Co. The student in writing his paper should make an effort to look up and tabulate a complete literature list. 11 CHAPTER III Breeds of Dairy Cattle and Mode of Recording in Each Breed List the breeds normally classified as dairy cattle with the names and addresses of their secretaries and the offices where the regis- tration takes place. Visit one of these offices and see how the business of registration is carried on, if this can be done. Make out proper registration papers for a calf and an adult bull or cow. Make out proper transfer papers. Review conditions for registration both past and present. How are imported cows registered? Write a 250-word paper comparing methods of registration in the different breeds. Answers to ques- tions like the following should be noted: How do unregistered ani- mals on the Jersey Isle differ from those in this country and what are the differences in mode of registration? REFERENCE U. S. Dept. Agr. Farmers' Bulletin 106, Breeds of Dairy Cattle. Blanks for registration and transfer of cattle are found in the text, pages 14-29. The history of changes in registration may be ob- tained from the herd book or from the breed associations. Point out any differences in the form of registration of transfer as adopted by the different breeds. 12 <* T3 o J5 > "5 °2 o tf n n O O q o TJH 00 €^ €© 2" 2" oo "o 'o c3 c3 u. 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Each student may be assigned a breed of dairy cattle in the United States to look up its advanced registry system, how it com- menced, by whom it was commenced, and what the requirements for entry were. What changes have been made in these require- ments since the beginning of the recording of these productivity records? In view of the history of the advanced registries write a paper on the suitability of the records for inheritance work and for the use of the breeder as a guide to his breeding operations. Note especially the possible influence of the requirement for entry, see M. S., chapter VIII. Let the student hunt up his own reference material in such sources as the Experiment Station Record. Supplementary exercise: Examine the rules of the different cow testing associations in this country and abroad for their adequacy in furnishing facts on which to base the following : 1. Selecting cattle for breeding. 2. Ease of pedigreeing animals. 3. When the pedigrees of an animal are made, the ease with which the production records of each ancestor may be added to the pedi- gree. 4. Determining a cow's own production and her probable subse- quent production. See also M. S., Chapter VI. 30 DEVELOPMENT OF PRODUCTIVITY REGISTERS 31 A lecture on the use of the herd book and advanced register in tracing a pedigree and searching out the records of different animals may well be included. It is suggested that this be a demonstration with a chance for the greatest freedom in asking questions by the class. CHAPTER V Tracing a Pedigree At the bottom of most practical breeding operations is the pedi - gree. The successful breeder must know how to trace a pedigree correctly and to interpret it properly after it is traced. If the pedi- gree is so important to the breeder it is equally important to the student of cattle breeding. In view of what is to follow the whole class should trace pedigrees of animals in the same breed. It is suggested that each student trace for four complete generations the pedigrees of four animals, two bulls and two cows. One bull and one cow to be noted Ad- vanced Registry animals, the other bull and cow to be chosen en- tirely at random 1 but to have neither Advanced Registry offspring nor records of their own. Each student is furnished with pedigree blanks in which he will fill in the pedigrees of the animals chosen. These are found on 1 A good way to choose the animals at random is to place in a hat 10 slips of paper numbered from to 9 and have the student draw from the hat. Suppose the student's first draw is 1, or the number in the 100,000 column would be 1. The student's second draw gives the 10,000 number, say the draw is 5; the third the 1000 number, say, is 9; the fourth, the 100, let us say is 2: the fifth, the tens, is 3; the sixth, the units, is 4. The number chosen is, consequently, 159,234, which would be the number of the animal that the student is to pedigree, pro- viding of course it has no Advanced Registry record. The slip is returned to the hat at each draw so there are always 10 slips from which to draw. In case the animal drawn has Advanced Registry records choose the next nearest ani- mal which has no such records. The bulls and cows that a given student pedigrees should if possible be chosen from the same volume of the herd book so as to eliminate the influence of more cows than bulls being recorded. Other- wise the animals pedigreed will be many years apart in dates of birth and consequently the younger one will have less chance of having the same ances- tors in a given generation than the animal of early birth. It is also important to have the random sample numbers approximately the same as those of the Advanced Registry. This may be done by allowing the two Advanced Regis- try animals already pedigreed to determine the first three places and drawing as above for the hundreds, tens, and units. 32 TRACING A PEDIGREE . 33 pages 35-40. A specimen pedigree of King Hengerveld Aaggie Fayne 56635, a Holstein-Friesian bull of merit is given on page 34. 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Furthermore, the purchaser's proper evaluation of such a pedigree for the breeding worth of the animal in question requires a knowledge of how such pedigrees are con- structed and the weight to be attached to the information given in them. In this sense the construction of such a pedigree furnishes a good ground work, to direct the student's attention to specific problems of breeding. The first step in commercial pedigree work is to trace the pedigree of the animal in the manner shown in the previous exercise. The next step is to add the records for production. The following in- formation should be given for each bull. A. Number of record daughters. B. Citation of records of some of the daughters featuring those which are best. C. Number of proven sons (sons who in turn have record daughters). D. Citation of records of some of the best of the proven sons' record daughters. E. Number of proven granddaughters and their exceptional records. F. Records of the dam and granddam, when commendable. G. Records of brothers or sisters, if striking. H. Records of other famous ancestors which would tend to enhance the value of the animal pedigreed. For the cow similar records are given, including first her own record. The present custom seems to require that all animals in the pedi- gree up to the fourth generation have some citation to records which would indicate their merit. The hardest pedigree to make attrac- tive is the one in which the ancestors have few available records. 41 42 MANUAL OF DAIRY CATTLE BREEDING Here is where the able salesman makes his money. Fill in two of the pedigrees with the information to show the breeding worth of the animal pedigreed. It is suggested that the first of these pedi- grees be for one of the Advanced Registry animals and the other for one of the random sample animals. Both of the pedigrees should be presented in sales catalog style. Chapters IX to XXIV of M. S. furnish information by which to evaluate the significance of different sorts of ancestors' records in predicting the milk yield or butter-fat percentage of a cow. REFERENCES Sales catalogues of good companies furnish one of the best sources for models of how this work should be done. Prescott, M. S., and Prescott, W. A. 1923. The Holstein-Friesian Founda- tion, Holstein-Friesian World, Inc., Syracuse, N. Y., gives some exten- sive pedigrees of high record cows with pedigree production records. CHAPTER VII Chaeacteeistics of Pedigeees in the Diffeeent Beeeds inbeeeding The distinction between inbreeding and line breeding is so hazily drawn that it is futile to consider them separately. The system of measuring inbreeding which is presented is that of Pearl. Chapter IV of Dr. Raymond Pearl's book on Modes of Research in Genetics should be consulted for a discussion of the method of measuring inbreeding before the student commences his own work. Inbreeding is noticed in any pedigree if within that pedigree there are two or more ancestors which are identical. In other words the different ancestors of an inbred animal are less in number than if that animal were not inbred. A purely objective measure of in- breeding is, then, the ratio between the number of different ancestors in one generation to the total possible number of ancestors. This is the measure used in this work. The pedigree of Rioter's Jersey Lad illustrating its calculation is given on page 45. The animals marked with the solid circles are repeated previously in the pedigree. Those marked with an open circle containing a cross are ancestors of repeated animals. In this . pedigree, the repeated animals are Ida's Rioter of St. Lambert, Bachelor of St. Lambert, Ida of St. Lambert and Ida's Stoke Pogis. The genera- tions are numbered Ai, A 2 , A 3 , A 4 . The coefficient of inbreeding is represented by Z. There are always two ancestors in Ai, conse- quently there is no inbreeding or Z = 0. In the second generation, A 2 , there are four possible ancestors and all four are different so there is no inbreeding, Zi = 0. In the third generation, A 3 , Ida's Rioter of St. Lambert reappears, so there is inbreeding. The amount of this inbreeding is equal to 1, the number of repeated ancestors, divided by 8 the possible number of ancestors, or 12.5 per cent of the inbreeding. In the fourth generation, there are 5 animals repeated, namely, Bachelor of St. Lambert (twice) 43 44 MANUAL OF DAIRY CATTLE BREEDING Ida of St. Lambert (twice) and Ida's Stoke Pogis (once). The number of total possible ancestors is 16 or the inbreeding, Z 3 = t% or 31.25 per cent. The student may calculate the inbreeding found in each of his four pedigrees. Tabulate the inbreeding of the pedigrees for the whole class, tabulating each group of pedigrees separately — Ad- vanced Registry bulls, Advanced Registry cows, random sample bulls, random sample cows. The protocol for this tabulation is given on pages 46-49. Comparing the average per cent of inbreed- ing for each group, what conclusion do you draw as to the influence of inbreeding on the possibilities of an animal's having an Advanced Registry record? Read Chapter VII in M . S. Sections relating to inbreeding in: REFERENCES Pearl, R., Gowen, J. W., and Miner, J. R. 1919. Studies in Milk Secretion VII. Transmitting qualities of Jersey sires for milk yield, butter-fat percentage, and butter-fat, Maine Station Bulletin 281. Wright, Sewall. 1922. The effects of inbreeding and crossbreeding on guinea pigs, U. S: Department of Agriculture, bulletins 1090 and 1121. King, Helen D. 1918, 1919, 1921. Studies in inbreeding, Jour. Exper. Zool., vol. 26, pp. 1-98; vol. 27, pp. 1-37; vol. 29, pp. 134-175. Write a paper of 250 words giving a synopsis of the conclusions you draw from your studies as to the influence of inbreeding. to to 4 u z o o+ -p CO ft o to^ o ft Z o to ^ C\2 M o d -p Z co o LO O Cj ■b ft o -p CTi ft_i z e ^b -p ^CO o TJ O d to Z m b CO ft O P. O CO h LO (d LO ej ^ O o- pq -p CO o C^ ft O^ o -d d ^ Z • K o tO s-H d o Z En O egg <*£ CD 6 CD Z ft z> r o o r o ft ft o H o P. d cc3 Z pq C\2 tO ^ d -H Z CO CD O o CV CD ft Pn < !>> Pi b o b o to •H o ft CD o -p CO o p. ft CO •H n b ft o P. CD -P O •H ft m ft o bf) o ft O ft mil '1 'q-S jo ^s^oth S.T3PI iP 2I0T> -o N 33^66 -on ,P X3g P'B'I ^9SJ8r S-,JQq.0TH 10099 -om 45 NAME OF BULL GROUP (ADVANCED REGISTRY BULL) H.B.No. 46 NO. NAME OF COW GROUP (ADVANCED REGISTRY COW) H.B.No. Zi Z 2 z 3 47 NO. NAME OF BULL GROUP (RANDOM SAMPLE BULL) H.B.No. Zi z 2 z 3 > » , 48 NO. NAME OF COW GROUP (RANDOM SAMPLE COW) H.B.No. Zi Z 2 z 3 _ 49 CHAPTER VIII Characteristics of Pedigrees for the Different Breeds relationship Within any pedigree a state of relationship exists if the sire and dam of the animal pedigreed have common ancestors, or putting it another way, two individuals are related if they have common ancestors. The calculation of the relationship coefficients is much like that for inbreeding save for one particular, namely, that for any one generation it is possible to have only half the number of animals related as compared with those which are inbred. Such being the case the denominator of the fraction in any generation is half the number of animals in that generation. The coefficient of kinship or relationship is noted by K. Turning back to the pedigree of Rioter's Jersey Lad, we note that there are no common ancestors for the sire and dam up to the fourth generation. Such being the case K 2 and K z are both in value. In the fourth generation A 4 , Bachelor of St. L. and Ida of St. L. are common to both sire and dam so that the coefficient of relationship is 2 divided by 8 or 25 per cent. The student may calculate the kinship found in each of his four pedigrees. Tabulate the kinship coefficients for the pedigrees of the whole class, tabulating each group separately as was done for the inbreeding. See pages 51-54 for protocols. Compare the average per cent of relationship found in the pedigrees of the four groups. What conclusion do you draw as to the influence of rela- tionship on the recorded producing power of an animal. REFERENCES Read Chapters II and VII of M. S. for the discussion of kinship. Maine Station Bulletin 281, Studies in milk secretion VII. Pearl, Raymond. September, 1917. Studies on inbreeding VII, American Naturalist, vol. LI, pp. 454-559. Other sources of information will be suggested by these references which it would be well for the student to follow up. Write a short paper on the influence of relationship. 50 NO. NAME OF BULL GROUP (ADVANCED REGISTRY BULL) H.B.No. Ki K 2 K* 51 NO. NAME OF COW GROUP (advanced registry cow) H.B.No. Ki K 2 K 3 ' 52 NO. NAME OF BULL GROUP (RANDOM SAMPLE BULL) H.B.No. K, K 2 Ks 53 NO. NAME OF COW GROUP (RANDOM SAMPLE COW r ) H.B.No. Ki K 2 Kg 54 CHAPTER IX Chaeacteristics of Pedigrees for the Different Breeds. Homozygosis Resulting from Different Types of Matings The reader will recall that an individual which is homozygous for a large number of factors will tend to have offspring more like himself than will an individual which is heterozygous for a wide number of factors. A sire homozygous for dominant factors will, consequently, practically always reproduce his kind, or be prepotent. The degree of homozygosis of a sire or cow is consequently of con- siderable importance to the breeder. The degree of homozygosis also has a further significance, in that a method of breeding which rapidly increases homozygosis in each generation tends to do two things — lessen the vigor of the offspring as measured by weight, fertility, and health, and second, increase the uniformity of the stock and consequently the prepotency in outside crosses. 3 Wright has indicated the methods by which the degree of homozygosis of an individual may be determined. The results give the probable average homozygosis as a per cent based on the assumption that the original ancestors were themselves random bred. REFERENCES In case the reader has not already done so it would be of interest for him to read: Wright. 1921. Systems of mating 1 to o, Genetics, vol. 6, pp. 111-178. Wright. 1922. Coefficients of inbreeding and relationship, American Natura- list, vol. 56, pp. 330-338. As an illustration of the method, I take the pedigree of King Walker 40358, a Holstein-Friesian bull (see page 56). 1 A word of comment should be added, while these effects are the average results of increase in homozygosis they may be avoided by careful selection to isolate the superior lines of the stock in each generation. This result brings in another agent, selection, which must be rigorously used on many characters to result in superior lines of homozygous stock. 55 h- LU ^ tU O I CJco 'b o ■b ft o l>5 P PS Cd CD ft 03 O *b O ■b © ft O © p PJ ft CQ 'b ft ft P 5h P ■H O 'b Jh — P M e e ^ ft • o ft 5h ft ^d •i~3 P *d ,|- D - Jm ft ct5 H •H P Sh Td cd 1 — 1 •H CO <m cd 5h cd S Sh ct3 Jm en ft ha CQ P • fe= CQ •H ft p • ^ CQ ft ft CO jxj rH ft a CD k ft Oj CQ 02& o O St §1 LO H CD •H m ^cS to . to m CO ^•p ft 0> ft 4^ 1-1 ^ 3^ CO ^ §5 C0^ LQ ^ CA2 ^ 0^ b CO 2 ^ft ft5 co^ ft""^ H ft to ^ ^ w ^ H ft< « ffl ^ 03 w a . ft . ft CD m . ft p . ft . -ft m . ft . ft . ? p O rH o ci! 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The average percentage of homozygosis is equal to J (1 + /o) X 100, or on a percentage scale of to 100 for the increase of homozygosis from 50 to complete homozygosis, 100 per cent, the value of / = #(l)n + n' + l( 1+/a ) where S equals summation. It is possible to consider f as Wright does, a coefficient of inbreed- ing. It is perhaps more properly the percentage increase of homo- zygosis brought about by the system of breeding. To increase homozygosis the ancestor must be common to both sire and dam. The n and n' are the number of generations from sire and dam re- spectively to the ancestor common to each. If the common an- cestor is inbred, its coefficient of inbreeding f must be worked out for his pedigree first. Otherwise the value of / is considered zero. The steps in the calculation of the pedigree of King Walker are as follows: King Walker has as common grandsire Admiral Walker. He also traces through the paternal grandsire and maternal grand- dam to Lillian Walker. All common lines tracing back from the sire to the common ancestor and thence forward to the dam and passing through no individual more than once are thus included. In tabular form we have f Q as given in the following protocol. INDIVIDUAL COMMON ANCESTORS OF SIRE AND DAM fa n n' 1 3 (l ) n + n' +1(1+/a) King Walker 40358 Admiral Walker 25755 Lillian Walker 38944 1 2 0.1250 0.0156 0.1406 or the per cent of probable homozygosis J (1 + 0.1406) = 57.03. As another illustration, the pedigree of the Holstein-Friesian cow Korndyke Butter Girl Johanna 2d, 183646 may be taken (see p.58). This pedigree displays a fairly large amount of inbreeding'. The animals repeated first are Korndyke Butter Boy, Johanna Aaggie 2d's Lad, Manor DeKol. The animals found in the pedigree of the repeated animals are shown as the open circles containing the cross. Korndyke Butter Boy is himself inbred so that it is neces- ° I b o c\2 id £^ ^ o M d CD Z P b O O ^ C\2 ® C\2 M CV2 g o- eg Z S to O CD Z PQ b ^ * g 6 cd 2 CD nd CN2 CD •H W) CD M * s § Z ha b 2 f° 2 >H o oo ^ <£) CO ° CD to .,_. •P d CD Z p b o cc5 O o CD z n b * o cd o b C\2 - Z CO O cd 1—1 <M . P Z Ha b to ^ CV2 S d Z CO O t5 CV2 H CD P Q> cd cvj a 6 -H Z CO o PQ 5m -p -p 2 . PQ Cv2 H o M tJ P to o b o W p a? P !>s o W ^d C\2 ■H W) W) cd < . cd cd P o Pa O -d cd P P -P ^D •r-D -P P b O P U -p ■P pq O M7 M d P to o o W P a? P d o P b o cd < cd C • cd P d O cd 1-3 P r o 5m ^p -p p P !>> d o o M P o cd cd P o H> & •r-3 ■P P b 5m ■p ■p p p ^d • o o W P o ^ 90^23 -on 6 82^01 -o N 6 X3 S 9^9281 -o N 58 CHAKACTEKISTICS OF PEDIGREES — HOMOZYGOSIS 59 sary to calculate his contribution to the homozygosis before cal- culating that of Korndyke Butter Girl Johanna 2d. Following the protocol we have the results shown below. INDIVIDUAL COMMON ANCESTORS OF SIRE AND DAM fa n 1 n' 1 1 2 (l)n+n'+i (1 +/ ) Korndyke Butter Boy 38496 Manor DeKol 21226 0.1250 Korndyke Butter Girl Johanna 2d 183646 Korndyke Butter Boy 38496 Johanna Aaggie 2d's Lad 26941 0.125 1 2 0.1406 0.0313 0.1719 The percentage of homozygosis is % (1 + 0.1719) X 100 =58.60 per cent. With these illustrations before us the complete significance of this coefficient may be considered further. As indicated above the coefficient gives the percentage increase of homozygosis or conversely the percentage decrease in heterozygosis, when the animal pedigreed has its unknown ancestors random mated. Thus the coefficient really gives the percentage decrease in heterozygosis relative to the stock to which the pedigrees are traced. If the percentage of heterozygosis happens to be 50 per cent in the latter stock, J (1 + F ) X 100 gives the percentage of homozygosis in the animals dealt with. In general, if p' is the percentage of heterozygosis in this foundation stock, the percentage of heterozygosis in the animal Oispo = v' (1 ~~ ^o) X 100. The assumption of previous random mating for the fourth generation animals in any fourth generation pedigree is undoubtedly not correct. While the actual percentage of heterozygosis in any stock can hardly be estimated, it is probably low when all the factors for the inherited characteristics of the species, genus, order, and phylum are considered. Thus what is really calculated, a point Wright is very careful to emphasize, is the degree of change in the direction of homozygosis. The impor- tance of the coefficient Fq is not to be minimized by these considera- tions but rather strengthened. Calculate the amount of homozygosis for each of the pedigrees. Tabulate the results for the whole class in the four groups, Ad- 60 MANUAL OF DAIRY CATTLE BREEDING vanced Registry bulls and cows, random sample bulls and cows. Protocols for these tabulations are found on pages 61-65. REFERENCE Wright's paper in 1923 on Mendelian Analysis of the Pure Breeds, II, The Dutchess Shorthorns, Journal Heredity, vol. XIV, pp. 405-422. INDI- VIDUAL COMMON ANCESTORS OF SIRE AND DAM fa n n' (!)n+n'+i (1 _L./ a ) Gl NO. ADVANCED REGISTRY GROUP, BULLS Individual Herd book No. ' — 1 62 ADVANCED REGISTRY GROUP, COWS PERCENTAGE OF HOMOZYGOSIS Individual Herd book No. V 63 NO. RANDOM SAMPLE GROUP, BULLS Individual Herd book No. 64 NO. RANDOM SAMPLE GROUP, COWS Individual Herd book No. - 05 CHAPTER X Characteristics of Pedigrees famous ancestors Statements like the following, make it desirable for the student to have an accurate acquaintance with the foundation animals in any breed. Of all the nearly eight thousand animals imported the real founda- tion of the aristocracy rests upon about three dozen animals. It is im- possible to measure exactly the contributions of the other 99 per cent of im- ported animals, but the preponderance of this small group in the pedigrees of our leading producers in both short-time and long-time tests and of our leading show ring winners as well, leads straight to the conclusion that it is prepotency of these blood lines that has been responsible for the supremacy of the breed. Each student may take the names of each ancestor in the pedi- grees he has just made, one ancestor for each slip. The cards found between manual pages 67-68 form an easy method of handling these data. A sample of the way one of these cards is made out is shown for Sir Johanna Butter Boy sire of Korndyke Butter Girl Johanna 2d. Herd Book No. 53405 Name of Ancestor Sir Johanna Butter Boy Sex Male Generation First In pedigree of Korndyke Butter Girl Johanna 2d 183646 The red slips are for the Advanced Registry bulls, green for the Advanced Registry cows, blue for the random sample bulls, and white for the random sample cows. In this way the different sets of pedigree data will not be mixed. When each student has arranged this data on the slips, have the slips of the whole class combined into four groups (Advanced Registry bulls, Advanced Registry cows, 66 s CO o 2 o o CQ o C 2 mm C o 1 g O 1 CO o 2 ■s o CQ 9m I u C 2 a) s i OQ & DC ! ! C o "■a 1 4) o 4) £ M 8 en o Z -8 o OQ 1 0) s a 2 4) I c in ■8 © I C O 4) e a? 8 CO © Z o 1 £ O 4=3 M O U C 0) it bl) EFFECT OF FAMOUS ANCESTORS 67 random sample bulls, random sample cows). Have each group sorted in order of the herd book number of the ancestor, tabulate the frequency of the appearance of the different ancestors in each group ; arrange in order of the frequency of appearance. Pages 68-72 give form tables to summarize most frequent ancestors. What do you conclude as to the ancestors found in the different groups of pedigrees? Are they different or are they the same? Do you note any significant difference between the four groups? Would the appearance of the most frequently appearing animal in the Advanced Registry group indicate the probable worth of any un- known animal? What would you consider the great families of the breed? After reading the following references write a short paper on this subject emphasizing especially its possible importance to produc- tion. Define family and write of interesting facts connected with each for the breeds you have studied. Critically review the data given in these references. REFERENCES M. S., chapters II and VII. Hunt, R. E. 1921. Who's who among Holstein-Friesian sires, Va. Agr. Col. Ext. Bui. 66, pp. 14. Hoven, J. M. 1916. Finding the prepotent sire, Jour. Heredity, vol. 7, pp. 173-178. Prescott, M. L., and W. A. 1923. Holstein-Friesian Foundations, Holstein- Friesian World, Inc., Syracuse, New York. Maine Station Bui., 281, 300, and 301. Frequency of Appearances of Different Ancestors in Advanced Registry Bull Groups BULLS NUMBER OF APPEARANCES IN GIVEN .GENERATION NUMBER OF ANCESTOR First Second Third Fourth Total COWS 68 Frequency of Appearance of Different Ancestors in Advanced Registry Cows Groups BULLS NUMBER OF APPEARANCES IN GIVEN GENERATION NUMBER OF ANCESTOR First Second Third Fourth Total COWS Frequency of Appearances of Different Ancestors in Random Sample Bulls Group BULLS NUMBER OF APPEARANCES IN GIVEN GENERATION NUMBER OF ANCESTOR First Second Third Fourth Total COWS 70 Frequency of Appearances of Different Ancestors in Random Sample Cows Group BULL3 XL' MB BR OF APPEARANCES I X GIVEN GENERATION First Second Third I ourth Total COWS Summary Sheet for Frequency of Appearances of Different Ancestors in Different Pedigree Groups. Animals Arranged in Order of the Total Number of Appearances, the Highest Coming First. NAME NUMBER OF APPEARANCES IN DIFFERENT GROUPS BULLS NUMBER Advanced Registry- group Random Sample group Total Bulls Cows Bulls Cows COWS 72 CHAPTER XI Conformation in Relation to Milk Yield This method of estimating the probable milk yield of a cow is of the rough and ready type. It is always available to the purchasers where milk records are not. Furthermore conformation gives an estimate of other qualities valuable in the cow besides the m ilk- yield itself, as for instance, present condition of the udder, type of cow in relation to gestation, etc. The study of conformation in relation to milk yield may be approached in the laboratory as follows — the class is supposed to have had a course in stock judging or its equivalent. The following information on the breed of animals they are studying should be given the students : the lowest, average, and the highest yearly milk yields of the cows in the breed as at- tained in the college barn. Place all of the animals now in the herd, estimating the probable yearly milk yield of each. After returning from the barn to the class room the actual yearly production of each cow should be procured. A three column protocol furnishing the necessary space is given on page 75. To bring out the facts of these data they may be arranged as follows. Arrange the student's estimate of yearly production in order from lowest to highest. Divide the whole data into five groups with equal numbers of cows. Calculate the average actual milk yield for the cows of each group. Plot these averages on coordinate paper on page 76 as shown in the protocol below. 6000 If line A, formed by connecting the five points,hasa generaltrend upward as the student's estimate of production increases, it shows 73 74 MANUAL OF DAIRY CATTLE BREEDING the student that he can judge cattle and pick out the better milkers. If it descends, it shows the student that he chooses the poorer milkers for the best and vice versa. Note: The method suggested is of course a rather crude test of this subject. It will, however, bring out the problem and set any student thinking about it. The correlation method can be sub- stituted where it is desired to do it. The student should write a short paper discussing results and present day significance of cattle judging especially in regard to practical dairying, using the following references to the history. REFERENCES M.S., Chapter III. Gowen, John W. 1920. Conformation and its relation to milk producing capacity in Jersey cattle, Jour. Dairy Science, vol. Ill, pp. 1-32. Gowen, John W. 1921. Conformation and its relation to milk producing capacity in Jersey cattle. II. The personal equation of the cattle judge, * vol. IV, pp. 359-374. Aldrich, A. M., and Dana, J. W. 1916. The relation of the milk veins system to production, Bui. 202 Vermont Agr. Expt. Sta., pp. 1-24. Graves, R. R. 1916. An experiment with milk veins, Hoards' Dairyman, III, pp. 687 and 717. Col. Le Couteur. 1845, 1851. Contribution to this subject in Jersey cattle is given in Jour. Royal Agr. Society of England, vol. V and vol. XII, part 2. These two papers are of much historical interest. Conformation in Relation to Milk Yield Breed Studied Range of Yearly Milk Yield NAME OF COW STODENT8 ESTIMATE OF Yi.AKI.V PRODI 1 1 [01 A' 1 1 W. MILE -i [ELD 75 76 CHAPTER XII Age of the Cow in Relation to Milk Yield The collection of data for this subject requires so much effort that the student must, practically speaking, take the scatter table of others for granted. For illustrative purposes, I take the tables for the relation of 365-day Guernsey milk yield with age. This is the ordinary correlation table used to show the relation of one variable to another (see page 78). The way in which such a table is made is as follows : Cards show- ing these records are first sorted into age groups of six months, be- ginning at one year and six months. These groups represent the frequency distribution shown under "Total" at the right. They are then sorted for the milk yield groups as shown above the table. The frequency distribution for each age is consequently the vari- ation of milk yield for each six months of age. If milk yield is related to age, the mean milk yields would be expected to rise or fall in some definite manner with increase in age. To get the mean milk yields for the age groups we adopt the method of arbitrary origins and call each class an increase of unity over the preceding class. The top line marked X shows these classes. The S(x) (summation x) of each row is found by multiplying the number in the row by the class unit in X and adding. Thus for the first row: (7X1) + (44 X 2) + (69 X 3) + (52 X 4) + (42 X 5) + (17 X 6) + (9 X 7) + (3 X 8) + (1 X 9) = 918 The mean milk yield of the first row may be obtained from this data by the following method: 918 s(x) n „ nnn „ = = 3.762295 244 n or in other words the mean milk yield of the row is 3.762295 units away from our arbitrary origin. Now each unit is equal to L000 77 MANUAL OF DAIRY CATTLE BREEDING X CO Tfl co b- O CO CO CO to" X o co" OOiONmOONCO^lMt^NNW COCOCOCOtOOOSOCSi— ii— i CO CD CO ^COCDi-HCDiOOSOr^iOCOCO^H — 00*" co co" co" -*" i-T —T £ -H CO CO -t- • O CO l^ X CSO^-iCOCO^PLOOt^XOSOi-HCO pno,I — CI O t^ CO OO Tf< CO Co" j-T o o OS PC OS o x CC 1- CO lO fiOOO(M01 , 1 , NffiHrfTftON OtOI^.CSCOOCOCOOt^"*COCO.— i lO'^.WNNCqHHH 000S2-000W 5- 1—1 00082 i 00022 00012 OO 00002 e> 00061 S" CO i-H 00081 g 1—1 1—1 1—1 i-i CO i-i CO r-i 000ZI ' ' i— i iO i— i CO CO i— i i—ii—i i— i i— i a - 00091 so 1 ' T*1 T Tf lo- COTjiTtiLOOCOCOCC CJ i— CO 00091 e* CO i-i CO c - co TfCONXC^CCOI'TfCO ooon g iO co o OS s CC - CCC!O(MN00N^0)IMMIM" 00081 s o o ca -r CO CI CO CO CO lOOOCOCSOOOOXTCl^ t-i CO CO i-h in CO i-h 00021 s CO OO CO (M co CC CO o CO 1^ co i— i i— icocococoiot^cscsrfeoi— i OOOII £ co tO CD 00 CO oc cc CO I- CO 00 00 tO tO COt^^^COCOCOi-ii-H 00001 S OS CO t^ b- CO 1^ o CO CI X OS o OS O "* CJ CO r- CI to CO OS CO CO tO to r}> 0006 s ^ "* CO T)H O CO CM o cc OC oo o CO o o COcOtOtOcOtOClXCOi— i G) CO N f OXt^tO-*COCOCOCOi-i 0008 S ci CO t^ ■^ CO CO © OS CO OS »o 00 o O OS b- CO CO TT 1 t>» CO CO CJ 06 tO to CO 05CON^MNHlMHH oooz 3 tO b- o i>- o tO CO co CO CI CO o CO s CI LO TPiON"01'Ttfn(Z)CoNC-ICO(Mi-i TH Tj( N H H H H 0009 § CC OS OS 00' OS CI >o CO 00 CO co 1- CSCOtO-rTiiOCOi— ii— i CO CO i— ii— i 0005 § -r OS -tf i— 1 t^ CO o CO CO CO r— ' i—i i—i ooos-oooi- Q '" CO CO CO CI r*l * O | f- R o CO CC O CO o CO o CC o OOCOOCOOCOOCOOOOOO ^ CO CO co co ~v ■^ lO O CO CD N N XXOSOSOOi— " i— i M AGE OF COW IN RELATION TO MILK YIELD 79 i— i LO ^h 00 <M i— i 00 00 -* — i *-< O) tO -f 1 S i CM CD CO 1i iO (D t^ OC IN OJ N IN CI M CO CO CO IN tt N CO — -*r o © 1- 1 1 1 1 1 1 ~ 1- 5 CM CM tO - •o ■ OS " 3 o CO i— 1 i-^ r— i 00 tO CM — CO 00 00 co CM CO N Th rH « co l— 1 i—l CO CO " r- tQ o CM o SB to CM OS 00' CO CO -DOCDOCDOCDOCC o 00 O CO MMM^^iOiOOC t-- t- 80 MANUAL OF DAIRY CATTLE BREEDING pounds of milk as seen from the method in which the table is grouped. The value of X is assumed to equal the mid-point of that particular group so that X = 1 is really equal to 4500 pounds of milk. The zero origin is consequently equal to 4500 — (1 ; the value of X, multiplied by 1000, the class interval) or 3500. Then the mean of the first group is equal to 3500 + 3.762295 X 1000 = 7262.3 pounds of milk In like manner the other average milk yields for the different ages may be obtained. These are shown in the following table. AGE AT TEST year 6 months to 1 year 11 months years months to 2 years 5 months years 6 months to 2 years 11 months years months to 3 years 5 months years 6 months to 3 years 11 months years months to 4 years 5 months years 6 months to 4 years 11 months years months to 5 years 5 months years 6 months to 5 years 11 months years months to 6 years 5 months years 6 months to 6 years 11 months years months to 7 years 5 months years 6 months to 7 years 11 months years months to 8 years 5 months years 6 months to 8 years 11 months, years months to 9 years 5 months, years 6 months to 9 years 11 months years months to 10 years 5 months, years 6 months to 10 years 11 months, years months to 11 years 5 months, years 6 months to 11 years 11 months, years months to 12 years 5 months, years 6 months to 12 years 11 months, years months to 13 years 5 months, years 6 months and above MEAN- MILK YIELD ,262 ,042 ,453 ,710 ,284 ,637 ,975 ,390 ,321 ,598 ,450 ,812 ,709 ,887 ,910 ,829 ,766 ,739 ,636 ,471 ,923 ,677 ,250 ,571 441 (The different members of the class may check the results for the different rows.) The student by plotting these means shows that there is a relation between milk yield and age of the cow. To place the milk yields of cows on comparable age basis we might use AGE OF COW IN RELATION TO MILK YIELD 1 the relation of these raw average milk yields at one age to those; of a constant age, say 8 years. However, it is better to determine the curve for the data thus eliminating the irregularities due to lack of numbers. Such a curve may be fitted to these data by the method of least squares. When thus fitted the curve is found to be: Mean milk yield = 6372.6 + 827.9a - 51.8a 2 + 1394.6 log (a - 1.25) where the age (a) is in years and the origin is zero years. The student may calculate the points in this curve for each six months of age beginning with 1 year 9 months and plot them on his plot of the raw average milk yield. The completed figure on page 85 when plotted from data of page 86 will be like that shown below. 3:9 5.<> 79 99 11-9 13V A(jE From these data the correction factors of milk yield for age may be determined. These factors are taken as the ratio of the milk yield at 8 years divided by the milk yield at the age from which correction is made. Thus the correction factor for the milk yields of cows at 2 years to the eight year standard would be 10837 2 7647.0 or 1.41; * This method of determining the correct ton factors lor age and milk yield is the one customarily employed with results which arc satisfactory for prac- tical purposes. A slightly more exact method takes into account not only the changes in the mean milk yields with age bul also the changes in the q504- 82 MANUAL OF DAIRY CATTLE BREEDING That is if a cow has a record of 8000 pounds as a two-year-old and we wish to get her probable record at 8 years we multiply 8000 X 1.417 or the probable record is 11,337 pounds. The class should determine these correction factors for different ages entering their results on pages 8-87 and make a table similar to that given in Maine Station Bulletin 311, page 17. The student will find a good deal of interest in making comparisons like these. Murne Cowan, 19797, has three records for Advanced Registry. Each record is for the year period. The first record is for 16,729 pounds of milk at 6 years 3 months of age. The second record is for 24,008 pounds of milk at 8 years 9 months of age. The third record is for 17,384 pounds of milk at 11 years 1 month of age. If we examine table 4 in Maine Station Bulletin 311 we note that in the six year age row, at 17,000 pounds of milk (column 15) the expected production of this cow at 8 years would be 17,682 pounds instead of the 24,008 pounds she actually produced. In other words, her production was 6326 pounds more than was ex- pected'. Before considering this difference, let us examine the third record. Figure 3 of this bulletin shows that, on the average, the cows at 11 years 1 month produce slightly more milk than those at 6 years 3 months. The 6 year 3 month record of Murne Cowan would consequently predict a record of about 17,000 pounds at 11 years 1 month old or a record closely similar to that actually made. This illustration brings out a true biological fact concern- ing milk records. The phenomenal record is made under such pres- sure that the cow, herself, and every condition surrounding her must be most favorable. Furthermore, the most favorable con- ditions for one cow may not be favorable to another so that it is extremely hard to duplicate the conditions which are favorable. The high records tend to be made when the cows are in the pink variation of milk yield with age. The formula which determines this rela- tion is milk yield at standard age (F s ) equals milk yield at x age (F x ) multi- plied by standard deviation of the milk yield at standard age (o- s ) divided by standard deviation at x age (<r x ), minus mean milk yield at x age (Yx) multiplied by standard deviation at standard age (cr s ) divided by standard deviation at x age (<t x ), plus average milk yield at standard age (F s ) or v _ ^ x °" s Fx q~s . — ' 6 — — T Is fy <Xx where the overlined value represents mean values. AGE OF COW IN RELATION TO MILK YIELD 83 of condition for making high records, the low records when the conditions are unfavorable. There is a tendency for high and low- record cows when retested to have their records regress toward the average of the breed, due to the change in conditions surrounding the cow. The correction on the basis of the mean curve lake- do cognizance of the environmental conditions but assumes that the conditions remain as they were in the first test. The method of correlations as given elsewhere takes the changing conditions into account. Both methods have their uses. In view of these facts, as illustrated by the records of Murne Cowan, what is the probable error within the limits of which we might expect the record of any one cow? The standard deviation of milk yield offers a means of determining this range. The stand- ard deviation of the milk yields of 8-year-old cows is 2335 or tha approximate probable error is 0.67449 X 2335 or 1575, or for any determination found in table 4 of Bulletin 311 of the Maine Station it is about an even chance that the actual milk yield of the cow will be within 1600 pounds either side of the figure shown. Thus for Murne Cowan's 6-year-old milk yield the probable 8-year production was 17,682 ± 1575 and the 11 year old milk yield predicted 17,695 =fc 1575 as the probable 8-year-old production. In her phenomenal record this cow produced much over this mark. In fact, it may be shown that there is only one chance in over 25,000 that a cow would make such a record as she actually did. The following references should be read: REFERENCES M. S., Chapter IV. Pearl, Raymond, and Patterson, S. W. 1917. The change of milk flow with age, as determined from the seven-day records of Jersey cattle, Annual Report of the Maine Agricultural Experiment Station, Bulletin 2(Y2, pp. 145-152. Pearl, Raymond, and Miner, John Rice. 1919. The variation of Ayrshire cows in the quantity and fat content of their milk, Jour. Agricultural Research, vol. XVII, pp. 285-322. Pearl, Raymond, Gowen, John W., and Miner, John Rice. 1919. Studies in milk secretion. VII. Transmitting qualities of Jersey sins for milk yield, butter-fat percentage, Annual report of the Maine Agricultural Experiment Station for 1919, Bulletin 281, pp. S9-2G4. Gowen, John W. 1920. Studies in milk secretion VIII. On the infim age on milk yield and butter-fat percentage, as determined from tin 84 MANUAL OF DAIRY CATTLE BREEDING day records of Holstein-Friesian cattle, Annual Report of the Maine Agricultural Experiment Station, Bulletin 293, pp. 185-196. Gowen, John W. 1923. Studies in milk secretion XIV. The effect of age on the milk yields and butter-fat percentages of Guernsey Advanced Registry cattle, Annual Report of the Maine Agricultural Experiment Station, Bulletin 311, pp. 9-20. Brody, Samuel, Ragsdale, Arthur C, and Turner, Charles W. 1923. The rate of growth of the dairy cow. IV. Growth and senescence as measured by the rise and fall of milk secretion with age, Jour. Gen. Physiology, vol. VI, pp. 31-40. N.-> Correction Factors for Milk Yield to a Standard Age WEAN MILK YIELD MULTIPLICATION FAOA TORS TO CORRECT TO V. 8-YEAR MILK YIELD 8 YEARS AS STAND- ( MILK YIELD OF AGE FOK WHICH CORRECTION IS TO BE MADE ARD AGE / 86 Milk Yields of Guernsey Advanced Registry Cows Corrected to an 8-Year Basis MILK YIELD AT GIVEN AGE AGE IN YEARS o o o © o o o o o o o o o o o o o o o o o o o 12000 13000 g o -r o o s 1 - o 9 MILK YIELD AT 8 YKAkS S7 CHAPTER XIII Age of the Cow in Relation to the Butter-fat Percentage This subject is much less complex than the same relations for milk yield. The relation is, in general, a linear one with a difference in the effect of age on the butter-fat percentage of the different breeds. The student will find it advantageous to calculate a table show- ing the raw data for the influence of age on the butter-fat percentage. These data may be found in the same references as those for the relation of age to milk yield. The method of calculation necessary to determine this relation of age to butter-fat percentage may be illustrated by the table on milk yield on page 78 although the linear equation is not suited to describe the relation of milk yield to age. Summation X (S(X)) for each row of the table is obtained as previously described, S(X) of the "Total" row is also calculated (37 X 1) + (389 X 2) + (1125 X 3) (1 X 17) + (1 X 21) = 61258. The sum of the right hand column, S(X) for each row is also equal to 61258 which checks the work thus far calculated. The figure 61258 is called S(X) of the table. The next constant needed is S(X 2 ). This is obtained by multiplying the totals of the lower row by the squares of the X row. Thus (37 X 1) + (389 X 4) + (1125 X 9) + (1800 X 16) + (2055 X 25) (IX 289) + (1 X 441) = 406680 = summation X 2 , written S(X 2 ). Similar values are now obtained for Y. Summation Y is equal to the totals of the right side of the table times the distance from the origin shown in column F. Thus S(Y) is equal to (244 X 1) + (2436 X 2) + (1287 X 3) + (1020 X 4) .... (1 X 31) + (1 X 33) = 65190 Summation Y 2 , (S(Y 2 )), is equal to the total column times the squares of the distance from the origin or (244 X 1) + (2436 X 4) + (1287 X 9) + (1020 X 16) .... (1 X 961) + (1 X 1089) = 607450 AGE OF COW AND BUTTER-FAT PERCENTAGE 89 The last constant needed is summation (XY). This is deter- mined by multiplying the summation of each row, S(X) for each row, by the value of Y, thus: (918 X 1) + (11063 X 2) + (6374 X 3) + (5314 X 4) .... (5 X 31) + (4 X 33) = 418940 From these data it is now possible to obtain the correlation of age with milk yield. This coefficient is obtained as follows. Each of the constants are divided through by the total number of indi- viduals in the table, 10644. 61258 10644 = 5.755167 S(X) n 406680 10644 " = 38.207441 S(X 2 ) n 65190 10644 = 6.124577 _S(Y) n 607450 10644 " = 57.069710 8(Y*) n 418940 = 39.359263 S(XY) 10644 To transfer our data to the true mean of the table, the following calculations are made. 38.207441 - (5.755167) 2 = 5.085494 = a~* 57.069710 - (6.124577) 2 = 19.559267 = <r y 2 39.359263 - (5.755167 X 6.124577) = 4.111300 In symbols this relation is S(X>) /S(X) n \ n S(Y*) : . (S(Y)\* _ n \ n J 2 = ax 2 ay' S(XY) S(X) S(Y) fQ /™ I+1 # X = value ot S(XYJ around the true mean. n n n The value of c x is equal to the square root of cr' 2 x or yjb. 085494 = 2.255104 90 MANUAL OF DAIRY CATTLE BREEDING The value of a y is equal to the square root of a 2 y or ->Jl9 .559267 = 4.422586 The value of the correlation coefficient is equal to S(XY) _ S(X) S(Y) 4.111300 n „ nnnn .. , , n n n or 0.412227 or in symbols 2.255104X4.422586 ax X ay The class interval, between 1 and 2 for instance of the X is equal to 1000 pounds of milk. The origin, on the A" scale, is equal to 3500 pounds of milk. In the same way the class interval for Y is equal to 0.5 of a year and the origin is equal to 1.25. From these data the mean average milk yield and age at test is found to be: 5.755167 X 1000 + 3500 = 9255 pounds of milk 6.124577 X 0.5 + 1.25 = 4.31 years of age The standard deviations for milk yield and age are equal to the a times the class interval, or : o-x X 1000 or 2.55104 X 1000 = 2255 pounds o-t X 0.5 or 4.422586 X 0.5 = 2.21 years There are two possible linear equations for this correlation table, one to give the mean milk yields when the age is known and the other to give the mean ages when the milk yields are given. The equations are equal to: 99^£ 9955 Mean milk yield = 9255 - 0.412 —^ 4.31 + 0.412 ^~ age, or mean milk yield = 7443 + 420.4 age. 2.21 2.21 Mean age = 4.31 - 0.412 rr — 9255 + 0.412 rr— milk yield, ZZoo ZZoo or mean age = 0.61 + 0.0004 milk yield. In symbols, the equations are: S.D. X S.D. X X = mean x - r XY g -^ mean Y + r XY g -p. Y O.JJ.y b.D.Y S.D. Y S.D. Y Y = mean Y - r XY -^ mean x + r XY a b.JJ.x b.JJ.x where S.D. is equal to the standard deviation. AGE OF COW AND BUTTER-FAT PERCENTAGE 91 As noted elsewhere the linear equations are not suited to the description of the relation between milk yield and age. The data are given merely for sake of illustration. It is realized that the description of the method is given in the most elementary terms. The student will find the reading of G. U. Yule, An introduction to the theory of statistics, J. B. Lippincott Company, Philadelphia, Chapters VI to X, of value. In the student's paper on the relation between age and butter-fat percentage in cattle, it would be desirable to take one of the numerous tables for these relations to be found in the references and check over the calculations and form the curves. The student would do well to consider and discuss the question of whether or not the effect of age on butter-fat percentage is the same in all breeds of cattle. REFERENCES See those of Chapter XI. CHAPTER XIV Mode of Secretion of Milk in the Udder This subject is still in its infancy so far as it concerns exact knowl- edge of how milk is actually secreted. The subject is, however, important enough for the student of heredity of milk yield to be reviewed by him. For the laboratory exercise, the review of the different original papers on this subject as cited in Chapter V of M . S. by different members of the class together with discussion of the conclusions drawn is suggested. It would also be desirable to have histological sections of udder tissue taken from an animal which had been completely milked out and from another before milking had commenced on demonstration for the students' micro- scopical study. Note should be taken of the size and character of the udder cells and the possibilities of distinguishing cell de- struction versus any other theory, such as the secretion of the milk solids by the cells, to account for the formation of milk by- the udder. The tissue for these sections might be obtained from slaughter houses where milking cows were killed, as for example where slightly diseased tubercular cattle were killed. Care should be taken to have good sections. These may possibly be obtained from the Histology section of the Biology department of the University. 92 CHAPTER XV Permanence of Milk Yield and Butter-fat Percentage It would be futile to study the inheritance of milk yield or to make Advanced Registry records if two major easily determined facts were not true: First, a record on one lactation should predict with reasonable certainty what the record in a subsequent lactation will be; second, as a corollary to this, a cow's milk record of one lactation should occupy the same relative position among the rec- ords of her herd companions that it does in another lactation. To test the accuracy with which these results follow from a study of cattle records the following tabulation of data is suggested (see pages 95-98). Take the data of the college cows preferably using the lactation record of a definite length, for all cows having two or more lacta- tions. Arrange the data so that all cows have records at two years, three years, and four years. Take the records of the cows at two years and arrange them in order of milk yield. Divide the group into as nearly four equal parts as possible, the first part to include the highest producing fourth of the cows, the next group the second highest producing fourth of the cows, the next group the third highest producing fourth of the cows, and the fourth group the lowest producing fourth of the cows. Calculate the average production of each group. Without changing the four groups calculate the average milk yield of each group for the same cows at three years of age and at four years of age. Plot the line showing the average production of the highest group, the second highest, the third highest and the lowest producing cows. What conclusions do you draw? Do the same for the butter-fat percentage. Write a short paper on this subject after reading the following references. <!3 94 MANUAL OF DAIRY CATTLE BREEDING REFERENCES M. S., Chapter VI. Gavin, William. 1913. Studies in milk records on the accuracy of estimating a cow's milking capacity by her first lactation yield, Jour. Agric. Science, vol. 5, pp. 377-391. Gowen, John W. 1920. Studies in milk secretion V. On the variations and correlations of milk secretion with age in Jersey cattle, Genetics, vol. 5, pp. 111-188. Gowen, John W. 1920. Studies in milk secretion VI. On the variation and correlations of butter-fat percentage with age in Jersey cattle, Genetics, vol. 5, pp. 249-324. Gowen, John W. 1923. Studies in milk secretion XI. The relation between the butter-fat percentage of one lactation and the butter-fat percentage of a subsequent lactation in Guernsey Advanced Registry cattle, Jour. Dairy Science, vol. VI, pp. 330-346. Gowen, John W. 1923. Studies in milk secretion X. The relation between the milk yield of one lactation with the milk yield of a subsequent lacta- tion in Guernsey Advanced Registry cattle, Jour. Dairy Science, vol. VI, pp. 102-121. Gowen, Marie S., and Gowen, John W. 1922. Studies in milk secretion XIII. The relation between milk yield and butter-fat percentage of the 7-day and 365-day tests of Holstein-Friesian Advanced Registry cattle, Annual Report of the Maine Agricultural Experiment Station Jor 1922, Bui. 306, pp. 21-60. Permanence of Milk Yield NAME OF COW (COWS ARRANGED ACCORDING TO 2-YEAR MILK YIELD) 2-YEAR MILK YIELD 3-YEAH MILK YIELD l-V.'. \l; MII.K YIELD ' 95 Permanence of Butter-Fat Percentage name of cow (cows arranged in order of 2-year butter-fat percentage) 2-YEAR BUTTER-FAT PERCENTAGE 3-YEAR BUTTER-FAT PERCENTAGE 4-YEAR BUTTER-FAT PERCENTAGE 96 97 |ff4![|iH|i||[|| ||1| ill ■r-^X.-I — III I |||[|mi||||i|[||||||||[miOT IB ■■■■■■■■■■ ■■•■■■■■■■■a iiliiiiiiiii »■■■■ ■■* ■■»■■ ■■■■■ ■■■ ::::: ::: ■■■■■ ■■■ :::;: ::: I = |ii||^III±liii||i |e1;::;::|;ee:je|| — 1±± i--- — i±i ::::#::::::: ::±::::::::±±± [Stli'i ' Hi iiliii r Hn | ■■■■a ■■■ liili ill ■■••■ aaa ■■■■■ ■■■ ■■■■a BBB ■!■■!!■■■ ::::::::: HI 1:1111:11 ■■■■■■■■■ ■■••I:::: ■■■■ami c | ; i i i :iiiiiii±iiiiiiiii:iiiii: j_ 1 1 LTTTTrf mm w&-- ■ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 :±iii:iii:iiiiiiiii::iii: f- II m n m UW ill l §ff ^w i§l Uff Rfff IliWI e^_: i:iiiIiiiii::ii::: 4----+ fillip M n 11 m •LI EEEfEEEEEEEEEEEEEEEEEEEE PWWffB pfMttlf ::|i:i:::i:ii:iiiiiiiiii 1 jjjllj ■ i 1 m i -\r~ 03 CHAPTER XVI Inheritance of Milk Yield from Dam to Daughter The student by this time is familiar with the herd book and Advanced Registries to such an extent that records may be easily found when wanted. The courageous student may be given the problem of finding his own original records for this study. He will need Advanced Registry record cows which have Advanced Regis- try record daughters. The milk yield records will have to be cor- rected for age by the methods previously given. With these rec- ords the direct comparison of the daughter's and dam's records may be made. This task is without much question too large for the limited time which may be devoted to this class. The next best thing is to take the records which have already been tabulated and have the student make the necessary calculations and deduce the results from them. The writer consequently suggests that the class take table 80 of M . S. (or some such table where the work of tabulating has already been done) and calculate from it the mean milk yields of the daugh- ters for each grade of milk yield of the dams in the manner given for exercise XII. Plot on cross section paper the average milk yields of the daughters for each grade of milk yield of the dam. What conclusions do you draw from this plot? After reading Chapters X, XI, XII, XIII, XIV, XV, and XVI in M. S. write a short paper on the inheritance of milk yield from the parents. Cross-section paper for this exercise is found on page 100. 99 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ■ •■■■■BBS •■■■■■■■■■ ■■■■■■■■•II ■■■■■■■■■■■■■■■■■■■■■■■■■■■■I 100 , CHAPTER XVII Influence of the Grandparents on the Granddaughters' Milk Yield The influence of the grandparents on the milk yields or butter- fat percentages of the granddaughters may be tested in the same manner as in exercise XVI. Table 138 of M. S. would be a good one for the student to calculate and from which to plot the average milk production of the granddaughters for the granddam of a given grade of milk yield. The conclusions derived from the plot should be considered in conjunction with a study of the results given in Chapters XX, XXI, XXII, and XXIII of M. S. Cross-section paper for this exercise is found on page 102. 101 102 CHAPTER XVIII The Inheritance of Milk and Butter-fat Percentage in Crosses of Animals Differing Widely in the Amounts of These Variables Each student may review critically one of the following references and report on it. After the reports, have a general discussion of the subject by the members of the class with the object of coordi- nating the work of the different investigations and deriving conclusion of general application. The object of the reviews should be foremost in mind, namely, how the particular work furnishes evidence on the problem of the inheritance of milk yield and butter- fat percentage and the effects of dominance, heterosis, etc. REFERENCES Castle, W. E. 1919. Inheritance of quantity and quality of milk production in dairy cattle, Proc. National Academy of Sciences, vol. 5, pp. 428-434. Lawritson, M. N., et al. 1919. Purebred sires effect herd improvement, Cir. 8, Nebraska Agric. Exper. Station, pp. 1-15. Olson, T. M., and Biggar, G. C. 1922. Influence of purebred dairy sires, South Dakota Agric. Exper. Station Bui. 198, pp. 434-467. Kildee, H. H., and McCandlish, A. C. 1916. Influence of environment and breeding in increasing dairy production, Iowa Agric. Exper. Station Bui. 165, pp. 383-402. McCandlish, A. C, and Winters, L. M. 1920. A study of bulls, Jour. Dairy Science, vol. 3, pp. 529-539. McCandlish, A. C. 1920. Environment and breeding as factors influencing milk production, Jour. Heredity, vol. XI, pp. 204-215. McCandlish, A. C, et al. 1919. Influence of environment and breeding in increasing dairy production — II, Iowa Agric. Exper. Station Bui. l sS . pp. 65-88. Van Norman, H. E. 1907. Influence of pure bred sires, Report of Penn. State College, pp. 129-145. Beam, A. L. 1915. A study of the dairy herd records of Pennsylvania Experi- ment Station, Report Penn. State College, pp. 349-386. Wilson, J. H. 1917. The effect of the sire on the herd, Vermont Agric. Exper. Station Bui. 202, pp. 39-44. 103 104 MANUAL OF DAIRY CATTLE BREEDING Hayden, C. C. 1916. The influence of sires on production, Ohio Station, Monthly Bui., vol. 1, pp. 211-215. Gaines, W. L. 1923. The inheritance of fat content of milk in dairy cattle, Proceedings Amer. Soc. Animal Production, pp. 29-32. Ellinger, T. U. 1923. The variation and inheritance of milk characters, Proceedings Nat. Acad. Sciences, vol. 9, pp. 111-116. Gowen, John W. 1920. Inheritance in crosses of dairy and beef breeds of cattle II. On the transmission of milk yield to the first generation, Jour. Heredity, vol. XI, pp. 300-314. Gowen, John W. 1920. Inheritance in crosses of dairy and beef breeds of cattle. III. Transmission of butter-fat percentage of the first genera- tion, Jour. Heredity, vol. XI, pp. 365-376. CHAPTER XIX The Chromosome Mechanism of Heredity in Relation to Dairy Cattle Inheritance The cytology of the germ cells of cattle has been worked out by Wodsedalek and Masui. These papers may be read and discussed. Problems showing the probable distribution of the sex chromosomes and the proportion of chromosomes received by the offspring from certain of their grandparents may be worked. This information should then be considered from the view point of the inheritance of milk yield and butter-fat percentage. If it is possible to obtain slides of cattle test is or ovary from the Biology department of the Uni- versity, the student will find it interesting to study them in the attempt to obtain the number of chromosomes and the manner in which they divide. Do not get discouraged if the first slides are not good for the material is difficult to fix properly; obtain fresh material and try fixing it again. REFERENCES MasuIj Kiyoshi. 1919. The spermatogenesis of domestic mammals II. The spermatogenesis of cattle (Bos taurus) . Jour. Coll. Agr. Tokyo Imperial Univ. 3: 277-403. Wodsedalek, J. E. 1920. Studies on the cells of cattle with special reference to the spermatogenesis, oogonia, and sex-determination, Biol. Bui., vol. 38, pp. 290-317. See also M. S„ Chapter XXIX. 105 BIBLIOGRAPHY The following references additional to those already given furnish a bibliography to most of the important papers on cattle breeding and inheritance. These papers deal with inheritance of such of the less important economic characters as coat color, twinning, cataract, etc. A brief review of these works is found in "A Resume of Cattle Inheri- tance," Bibliographia Genetica, II: 287-337. Allen, C. L. 1922. The effect of the age of sire and dam on the quality of offspring in dairy cows, Jour. Heredity, 13, pp. 167-176. See also Holstein Friesian World, 20 (1923), No. 17, pp. 817-819, 832. Barrington, Amy, and Pearson, Karl. 1905. On the inheritance of coat color in cattle. Part I. Shorthorn crosses and pure Shorthorns, Biometrika, 4, pp. 427-464. Bateson, W., and Saunders, E. 1902. Experimental studies in the physi- ology of heredity, Roy. Soc. (London), Rpts. Evol. Com., Xo. 1, pp. 3-160. Boyd, M. M. 1908. A short account of an experiment in crossing the American bison with domestic cattle, American Breeders' Assoc. Proc, 4, pp. 324-331. Boyd, M. M. 1914. Crossing bison and cattle, Jour. Heredity, V, pp. 189-197. Brun, J. 1922. Biometrical and hereditary studies of the escutcheons of cows, Jahrb. Wiss. u. Prakt. Tierzucht, 15, pp. 72-124. Campbell, M. H. 1924. Inheritance of black and red coat colors in cattle. Genetics, 9, pp. 419-441. Castle, W. E., and Wachter, W. L. 1921. Genetics of Hereford Cattle, Jour. Heredity, 12, pp. 36-39. Cole, L. J. 1916. Twinning in cattle with special reference to tin fro martin. Science, N. S., 43, pp. 177-178. Cole, L. J. 1919. A defect of hair and teeth in cattle, probably hereditary, Jour. Heredity, 10, pp. 303-306. Cole, L. J. 1920. Inheritance of milk and meat production in cattle, \\ is. Sta. Bull., 319, pp. 53, 54. Van Damme, C. 1908. Inheritance of coat color in the cattle of East Flan- ders, Rev. Gen. Agron. n. Ser., 3, pp. 363 365. Detlefsen, J. A. 1920. .4 herd of albino cattle. Jour. Heredity, 11. pp. 378- 379. Detlefsen, J. A., and Yapp, W. \Y. 1920. The inheritance of congenital cataract in cattle, Amer. Nat., 5 1 : 277 280. 107 108 MANUAL OF DAIRY CATTLE BREEDING Duck, Russel W. 1923. Colors of Shorthorn cattle, Jour. Heredity 14: 65-75. Dunn, L. C, Webb, H. F., and Schneider, M. 1923. The inheritance of spotting in Holstein-Friesian cattle, Jour. Heredity 14: 229-240. Fogle, P. E. 1910. Results from breeding grade Shorthorns to Hereford bull, Amer. Breeders' Assoc. Proc., 6, pp. 373-375. Fogle, P. E. 1912. Transmission of color and color markings in Hereford- Shorthorn crosses, Amer. Breeders' Jour., 3-4, pp. 201-204. Funkquist, H. 1920. The inheritance of muzzle color in the cattle breed of Stjernsund, Hereditas, 1, pp. 343-363. Funkquist, H., and Boman, Nils. 1923. Vererbung u Weisser Abzeichem" bei Rindern, Hereditas 4: 65-80. Goodnight, C. 1914. My experience with bison hybrids, Jour. Heredity, 5, pp. 197-199. Gowen, John W. 1918. Studies in inheritance of certain characters of crosses between dairy and beef breeds of cattle, Jour. Agr. Research, XV, pp. 1-57. Gowen; John W. 1918. Inheritance studies of certain color and horn charac- ters in first generation crosses of dairy and beef breeds, Maine Agr. Expt. Station Annual Report' for 1918. Bulletin 272, pp. 129-148. Gowen, John W. 1918. Report of progress on animal husbandry investiga- tions in 1917. Annual Report of the Maine Agr. Expt. Station for 1918, Bulletin 274, pp. 205-228. Gowen, John W. 1919. Studies on milk secretion. IV. On the variation and mode of secretion of milk solids, Jour. Agr. Research XVI, pp. 79-102. Gowen, John W. 1919. Report of progress on animal husbandry investiga- tions in 1919. Annual Report of the Maine Agr. Expt. Station for 1919, Bulletin 283, pp. 249-284. Gowen, John W. 1920. Studies in milk secretion. VII. On the variations and correlations of butter-fat percentage with age in Jersey cattle, Genetics 5: 249-324. Gowen, John W. 1921. Report of progress on animal husbandry investiga- tions in 1920. Annual Report of the Maine Agr. Expt. Station for 1921, Bulletin 299, pp. 85-120. Gowen, John W. 1922. Identical twins in cattle? Biol. Bull. XLI, pp. 1-6. Gowen, John W. 1923. Studies on conformation in relation to milk produc- ing capacity in cattle. III. Conformation and milk yield in the light of the personal equation of the dairy cattle judge, Annual Report Maine Agr. Expt. Station for 1923, Bulletin 314, pp. 69-96. Gowen, John W. 1924. Intrauterine development of the bovine fetus in rela- tion to milk yield in Guernsey cattle, Journal Dairy Science, 7: 311-317. Gowen, John W. 1924. Inheritance of milk production, Sci. Agr., IV, pp. 365-380. Gowen, John W. 1924. The application of the science of genetics to the farmers' problems, Sci. Agr., V., pp. 1-12. Gowen, John W., and Covell, Mildred R. 1921. Studies in milk secre- tion. IX. On the performance of the progeny of Holstein-Friesian BIBLIOGRAPHY 109 sires, Annual Report of the Maine Agr. Expt. Station for 1921, Bull. 300, pp. 121-252. Gowen, John W., and Covell, Mildred R. 1921. Studies in milk secre- tion. XII. Transmitting qualities of Holstein-Friesian sires for milk yield, butter-fat percentage, and butter-fat. Annual Report of the Maine Agr. Expt. Station for 1921, Bull. 301, 253-308. Hammond, J. 1920. On the relative growth and development of various breeds and crosses of cattle, Jour. Agric. Sci., 10: 233-289. Hayden, C. C. 1922. A case of twinning in dairy cattle, Ohio Sta. Mo. Bui. 7, No. 3-4, pp. 54-57. Hayden, C. C. 1922. A case of twinning in dairy cattle, Jour. Heredity, 13: 22-24. Hays, F. A. 1919. Inbreeding animals, Delaware Agric. Expt. Station Bull., 123, pp. 1-49. Hesse, G. 1913. Inbreeding and heredity studies with cattle of the West Prussian Herd book, Arb. Deut. Gesell. Ztichtungsk., No. 18, pp. VI + 215. Hills, F. B., and Boland, E. N. 1913. Segregation of fat factors in milk production, Proc. Iowa Acad. Sci., 20, pp. 195-198. Hooper, J. J. 1919. Inheritance of Jersey colors, Jour. Dairy Sci., 2: 290-292. Hooper, J. J. 1920. A study of inheritance of coat colors in Jersey cattle, Science 52: 43. July 9. Color of crossbred calves, Jour. Heredity, 12: p. 480. Studies of dairy cattle, Kentucky Sta. Bui., 234, pp. Hooper, J. J. 1921 Hooper, J. J. 1921 91-161. Jones, Sarah V. H, and Rouse, James E. 1920. The relation of age of dam to observed fecundity in domesticated animals. I. Multiple birth in cattle and sheep, Jour. Dairy Sci., 3: 260-290. Kirchner, W. 1901. Influence of heredity upon the percentage of butter-fat in milk, Mitt. Landw. Inst. Univ. Leipzig, No. 2, pp. 129-139. Kuiper, K. 1921. Color inheritance in cattle, Jour. Heredity, 12: 102-109. Laughlin, H. H. 1911-1912. The inheritance of color in Shorthorn cattle, Amer. Nat., 45, pp. 705-742, 46, pp. 5-28. Lillie, Frank R. 1917-1918. The freemartin, a study of the action of sex hormones in the foetal life of cattle, Jour. Exp. Zool., 23, 371-452, Abst. in Jour. Roy. Microsc. Soc, 1918, 37-38. Lillie, Frank R. 1923. Supplementary notes on twins in cattle, Biol. Bull., 44, pp. 47-78. Lloyd-Jones, O., and Evvard J. 1916. Inheritance of color ami horns in blue-gray cattle, Iowa Sta. Research Bui., 30, pp. 67a 106a. Lush, J. L. 1922. An hereditary notch in the ears of Jersey cattle, Jour. Heredity, 13, pp. 8-13. Marshall, F. R. 1914. Holstein milk yield, Jour. Heredity, 4. pp. 437 139, Nabours, R. K. 1912. Evidence of alternative inheritance in the F- : genera- Hon from crosses of Bos indicus on B. taunts, American Nat., 46, pp. 428-436. 110 MANUAL OF DAIRY CATTLE BREEDING Parlour, W. 1913. Jersey-Angus cattle, Live Stock Jour. (London), 77, No. 2025, p. 85. Pearl, Raymond. 1912. A case of triplet calves, with some general considera- tions regarding multiple gestation in normally uniparous animals, Maine Agr. Expt. Station Annual Report for 1912, Bulletin 204, pp. 259-282. Pearl, Raymond. 1913. A contribution towards an analysis of the problem of inbreeding, American Naturalist, XLVII, pp. 577-614. Pearl, Raymond. 1913. Variation in the tongue color of Jersey cattle. Proceedings of the Society for the Promotion of Agricultural Science, pp. 49-57. Pearl, Raymond. 1913. Constants for normal variation in the fat content of mixed milk, Maine Agr. Expt. Station Annual Report for 1913, pp. 299-305. Pearl, Raymond. 1914. On the results of inbreeding a mendelian popula- tion: a correction and extension of previous conclusions, American Naturalist, XLVIII, pp. 57-62. Pearl, Raymond. 1914. Studies on inbreeding. IV. On a general formula for the constitution of nth generation of a mendelian population in which all matings are of brother X sister, American Naturalist, XLVIII, pp. 491-494. Pearl, Raymond. 1914. Studies on inbreeding. V. Inbreeding and rela- tionship coefficients, American Naturalist, XLVIII, pp. 513-523. Pearl, Raymond. 1914. On the law relating milk flow to age in dairy cattle, Proceedings of the Society for Experimental Biology and Medicine, XII, pp. 18-19. Pearl, Raymond. 1915. Studies on inbreeding. VI. Some further con- siderations regarding cousin and related kinds of mating, American Naturalist, XLIX, pp. 570-575. Pearl, Raymond. 1916. Reports of progress on animal husbandry investiga- tions in 1915, Me. Agr. Expt. Sta. Circ, 519, pp. 1-27. Pearl, Raymond. 1917. Report of progress on animal husbandry investiga- tions in 1916. Annual Report of Maine Agr. Expt. Station for 1917, Bulletin 261, pp. 121-144. Pearl, Raymond. 1918. Studies on inbreeding . VIII. A single numerical measure of the total amount of inbreeding, Amer. Nat., LI, pp. 636-639. Pearl, Raymond, and Miner, John Rice. 1913. Tables for calculating coefficients of inbreeding, Maine Agr. Expt. Station, Annual Report for 1913, pp. 191-202. Pearl, Raymond, and Patterson, S. W. 1917. The change of milk flow with age, as determined from the seven day records of Jersey cattle, Annual Report, Maine Agr. Expt. Station, Bulletin 262, pp. 145-152. Pearson, K. 1910. Note on the separate inheritance of quantity and quality in cow's milk, Biometrika, 7, pp. 548-550. Peters, J. 1913. Inheritance of milk production and its significance to cow- testing association, Deut Landw. Tierzucht, 17, Nos. 11, pp. 121-125; 12, pp. 133-135; 13, pp. 145-149. BIBLIOGRAPHY 111 Pitt, Frances. 1920. Notes on the inheritance of colour and markings in pedigree Hereford cattle, Jour. Genetics, 9: 281-302. Putney, F. S. 1910. The theory of dynamic heredity in the light of data gathered from the dairy herd of the Missouri Agricultural College, Amer. Breeders Assoc. Proc, 6, pp. 310-317. Richardson. 1914. Heredity of color in cattle, Deut. Landw. Tierzucht, 18, No. 6, pp. 61-65. Rietz, H. L. 1909. On inheritance in the production of butter-fat, Biome- trika, 7, pp. 106-126. Roberts, E. 1921. Polydactylism in cattle, Jour. Heredity, 12, pp. 84-86. Smith, A. D. B. 1925. Color inheritance in Shorthorn cattle, Jour. Heredity, 16, pp.. 73-84. Spillman, W. J. 1905. Mendel's law in relation to animal breeding, American Breeders Assoc. Proc, 1, pp. 171-177. Spillman, W. J. 1913. Inheritance of the poll character in cattle, Annual Report Amer. Polled Jersey Cattle Co., pp. 8. Stevens, H. D. E. 1913. Jersey-Angus cattle, Live Stock Jour. (London) 77, No. 2025, p. 132. Storer, J. The wild white cattle of Great Britain, Lond., pp. 234. Tandler, Julius, and Keller, Karl. Uber das Verhalten des Chorions bei verschiedengeschlechtlicher Z willing sgraviditdt des Rindes und uber die Morphologie des Genitales der Weiblichen Tiere welche einer sol- chen Graviditdtentstammen, Deutsche Tierarzt. Wochenschrift, Jahrg. '19. Templeton, G. S. 1923. Unusual color inheritance, Jour. Heredity, 14: 39-40. Uhlman, E. 1914. The inheritance of twin calving in cattle, Deut. Landw. Tierzucht, 18, No. 14, pp. 163-164. Watson, J. A. S. 1919. Problems of animal breeding, Scottish Jour. Agric, 2: 449-456. Watson, J. A. S. 1921. A mendelian experiment with Aberdeen-Angus and West Highland cattle, Jour. Genetics, 11, pp. 59-67. Wentworth, E. N. 1912. Concerning li blue-gray" cattle, Amer. Breeders Mag. 5, No. 2, pp. 9, 10. Wentworth, E. N. 1913. Color in Shorthorn Cattle, Amer. Breeders Mag. 4, pp. No. 202-208. Wentworth, E. N. 1916. A sex-limited color in Ayrshire cattle, I . S. Dept. Agr. Jour. Agr. Research, 7, pp. 141-147. Wilson, J. 1908. Mendelian characters among Shorthorn cattle, Sci. Proc. Roy. Dublin Soc, n. ser., 11, No. 28, pp. 317-324. Wilson, J. 1909. The colors of Highland cattle, Sci. Proc Roy. Dublin Soc, n. ser., 12, pp. 66-76. Wilson, J. 1910. The separate inheritance of quality and quantity if milk, Sci. Proc. Roy. Dublin Soc, n. ser., 12, pp. 170 17'.». Wilson, J. 1911. The inheritance of mill: yield in cattle, Sci. Proc. Roy. Dublin Soc, n. ser., 13, pp. 89 L13. 112 MANUAL OF DAIRY CATTLE BREEDING Wodsedalek, J. E. 1918. Cytological studies of the reproductive cells of cattle, Idaho Sta. Rpt., 1918, p. 34. Woodward, T. E. 1916. Is the ability to produce milk fat transmitted by the dam or by the siref, Hoard's Dairyman, 51, p. 146. Wriedt, C. 1919. The brindle color in cattle in relation to red, Jour. Genetics, 9, p. 83. Wriedt, C. 1924. Formalism in breeding of live-stock and modern research on heredity. Rev. Sci. and Pract. Agr. N. S. 2, pp. 325-331. Wriedt, C. 1925. Colorsided cattle. Jour. Heredity, 16, pp. 51-56. Wright, S. 1917. Color inheritance in mammals. VI. Cattle, Jour. Hered- ity, 8, pp. 521-527. Yamane, J. 1915. On the inheritance of an aural abnormality in the Ayrshire cattle, Jour. Gol. Agr. Tohoku Imp. Univ., 6, No. 7, pp. 166-170. INDEX Age in relation to butter-fat per- centage, 88 Age in relation to milk yield, 77 averages for different ages, 80 correlation table, 78 curve, 81 Application for registry, 14 Application for transfer, 18 Butter-fat percentage and age, 88 inheritance in crosses, 103 permanence of, 93 Breeds modes of recording, 12 application for registry, 14 application for transfer, 18 origin and early history of, 9 registration of, 11 influence of, 11 productivity, 30 Chromosomes, 105 Conformation in relation to milk yield, 73 Correlation, 77 calculation of, 77, 88 Famous ancestors in pedigrees, 66 Homoz3 r gosis in pedigrees, 55 Inbreeding in pedigrees, 43 Inheritance in crosses, 103 King Hengerveld Aaggie Fayne, pedigree of, 34 King Walker, pedigree of, 56 Korndyke Butter Girl Johanna 2d, pedigree of, 58 Milk inheritance in crosses, 103 mode of secretion, 92 permanence of yield, 93 yield and age, 77 correlation table, 78 curve showing relation, 81 for different ages, 80 Pedigrees famous ancestors in, 66 homozygosis in, 55 inbreeding in, 43 King Hengerveld Aaggie Fayne, 34 King Walker, 56 Korndyke Butter Girl Johanna 2d, 58 relationship in, 50 Rioter's Jersey Lad, 45 sales, 41 tracing, 32 Permanence of butter-fat, 93 Permanence of milk yield, 93 Registry, application for, 14 Relationship in pedigrees, 50 Rioter's Jersey Lad, pedigree of, 45 Transfer, application for, IS 113 Sans Tache Sans Tache IN THE "elder days of art" each artist or craftsman enjoyed the privilege of independent creation. 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